Evaluation of a Commercial High-Protein Distiller’s Dried Grain with Solubles (HP-DDGS) Product in the Diet of Juvenile Nile Tilapia (Oreochromis niloticus)
Blaine A. Suehs, Delbert M. Gatlin
Abstract
A comparative feeding trial and digestibility determination were conducted to evaluate the nutritional value of a commercial, high-protein distiller’s dried grains with solubles (HP-DDGS) ingredient in the diet of Nile tilapia (Oreochromis niloticus). For the feeding trial, six diets were formulated to contain 360 g total dietary protein kg-1 and were prepared with incremental levels of protein from the HP-DDGS (0, 75, 150, 225, 300, and 375 g of dietary protein kg-1) replacing protein from fishmeal and soybean meal. Juvenile tilapia ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:mn>10.4</a:mn> <a:mtext> </a:mtext> <a:mtext>g</a:mtext> <a:mo>±</a:mo> <a:mn>0.37</a:mn> </a:math> ; <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" id="M2"> <c:mtext>average</c:mtext> <c:mtext> </c:mtext> <c:mtext>initial</c:mtext> <c:mtext> </c:mtext> <c:mtext>weight</c:mtext> <c:mo>±</c:mo> <c:mtext>SD</c:mtext> </c:math> ) were evenly distributed in 24, 38-L aquaria operated as a recirculating system and fed twice daily to apparent satiation throughout the 8-week trial. Nile tilapia exhibited no significant ( <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" id="M3"> <e:mi>P</e:mi> <e:mo>></e:mo> <e:mn>0.05</e:mn> </e:math> ) differences in weight gain, feed efficiency, condition indices, whole-body proximate composition, or innate immunological responses when fed any DDGS-supplemented diets compared to the control diet. Percent apparent digestibility coefficients (ADCs) of the DDGS product for organic matter, crude protein, and gross energy were 74.8%, 83%, and 82.8%, respectively. Availability values for all amino acids were 89% or greater. Thus, this high-protein DDGS was established as a readily digestible protein feedstuff suitable for replacing soybean meal and fishmeal at up to 375 g of total dietary protein kg-1 in a practical diet for Nile tilapia.